Expression of vascular endothelial growth factor in human adrenals

Angiogenesis is an important component in many biological processes and also in pathologic conditions including neoplastic diseases. Vascular endothelial growth factor (VEGF) is a secreted endothelial cell-specific growth factor, which is induced by tissue hypoxia and is angiogenic in vivo. Adrenal gland is a well-vascularized organ, and the roles of VEGF in normal adrenal and in adrenal tumorigenesis is not well characterized. We therefore investigated VEGF mRNA expression in normal human adrenals and in cultured adrenocortical cells. VEGF mRNA was constantly expressed in normal adrenals as well as in cultured adrenocortical cells. The mRNA levels were increased after 24h stimulation with either ACTH or cAMP. The effect of cAMP was dose-dependent. This suggests that ACTH-induced VEGF mRNA expression is mediated via protein kinase A dependent pathway.

Child rate, pregnancy outcome and ovarian function in females with classical 21-hydroxylase deficiency

BACKGROUND

Ovulatory disorders and decreased fertility rates have been found in females with classical 21-hydroxylase deficiency (21-OHD). We analyzed the pregnancies of 29 females with classical 21-hydroxylase deficiency and examined 16 of these women in a cross-sectional study.

METHODS

The child rate of the 29 patients was compared with that in the general Finnish female population with equal age distribution.The cross-sectional study of the 16 patients included a standardized questionnaire, clinical examination, ultrasonography of the internal genitalia, basal measurements of serum steroids, sex hormone binding globulin, PRL, gonadotropins and plasma ACTH.

RESULTS

The child rate was significantly lower than that in the general population (0.34 vs 0.91; p<0.001). A total of 13 pregnancies could be registered. From these pregnancies, ten healthy children were born, all for females with a simple virilizing disease. None of the nine females with salt wasting 21-OHD had any children or had sought treatment for infertility. In the cross-sectional study, females with regular menses (5/16; 31%) had well controlled adrenal androgen secretion and they had normal serum progesterone concentrations whereas the females with irregular menses (11/16; 69%) were often undersubstituted and presented with high serum progesterone concentration in the follicular phase. Polycystic ovaries could not be detected in any of these patients.

CONCLUSIONS

Females with simple virilizing 21-OHD often have irregular menses but their final prognosis for fertility seems to be better than previously reported. On the contrary, our study confirms the extremely low child rate in the salt wasting group.

Expression of low and high density lipoprotein receptor genes in human adrenals

Corticosteroids are synthesized from cholesterol which may arise from de novo synthesis or from the uptake of low or high density lipoproteins (LDL or HDL). In the present study, we compared the expression and regulation patterns of LDL receptor and CLA-1 (CD36 and LIMPII Analogous-1, an HDL receptor) genes in adult human adrenocortical tissues to shed more light on the relative contribution of LDL and HDL in human adrenal steroidogenesis. By screening 64 normal and pathological adrenal samples by Northern blotting, we found a positive correlation between LDL receptor and CLA-1 mRNA expression in the adrenal tissues (r=0.547; spearman rank correlation test P<0.01). Adrenal tissues adjacent to Cushing's adenomas contained consistently less LDL receptor and CLA-1 mRNA than normal adrenals (Mann-Whitney P<0.05). In primary cultures of normal adrenal cells, accumulation of both LDL receptor and CLA-1 mRNAs was upregulated by ACTH in a dose- and time-dependent manner, with an earlier induction of LDL receptor than CLA-1 mRNA expression. (Bu)(2)cAMP also increased the levels of these two mRNAs. Addition of LDL, but not HDL, into the culture medium increased cortisol production in untreated adrenocortical cells. Both LDL and HDL enhanced ACTH-induced cortisol production, with the effect of LDL much stronger than that of HDL. Our data show that LDL receptor and CLA-1's expression is ACTH-dependent and occurs in parallel in human adrenal tissues. LDL rather than HDL may be used as the preferential source of cholesterol for steroidogenesis in human adult adrenocortical cells.

Expression of inhibin alpha in adrenocortical tumours reflects the hormonal status of the neoplasm

Inhibins are gonadal glycoprotein hormones whose main endocrine function is to inhibit pituitary FSH secretion. In addition to testes and ovaries, other steroid-producing organs are sites of inhibin alpha subunit expression. To study the role of inhibins in human adrenal gland, we screened a panel of 150 adrenals (10 normal adrenals, 25 adrenocortical hyperplasias, 65 adrenocortical adenomas, 30 adrenocortical carcinomas and 20 phaeochromocytomas) for inhibin alpha expression. mRNA levels of inhibin alpha subunit were studied in 57 samples and all tissues were stained immunohistochemically with an inhibin alpha subunit-specific antibody. Inhibin alpha mRNA was detected in all adrenocortical tissues. Virilizing adenomas possessed a 10-fold higher median inhibin alpha mRNA expression than did normal adrenals. Bilaterally and nodularly hyperplastic adrenals and other than virilizing adrenocortical tumours had their median inhibin alpha mRNA levels close to those of normal adrenals. Immunohistochemically, inhibin alpha subunit was detectable in all normal and hyperplastic adrenals, as well as in 73% of the adrenocortical tumours. However, the percentage of inhibin alpha-positive cells varied greatly in different tumour types. The median percentage of positive cells was 10 in non-functional and Conn's adenomas, 30 in Cushing's adenomas and 75 in virilizing adenomas. In malignant adrenocortical tumours the median percentage of inhibin alpha-immunopositive cells was 20 in non-functional carcinomas, 30 in Conn's carcinomas, 65 in Cushing's carcinomas and 75 in virilizing carcinomas. All phaeochromocytomas were negative for inhibin alpha subunit both at the mRNA level and immunohistochemically. Our data show that inhibin alpha subunit is highly expressed in both normal and neoplastic androgen-producing adrenocortical cells, with less expression in cortisol-producing and hardly any in aldosterone-producing cells. This suggests a specific role for inhibins in the regulation of adrenal androgen production. We did not find any significant difference in inhibin alpha expression between benign and malignant adrenocortical tumours. Thus inhibin alpha gene does not seem to have a tumour suppressor role in human adrenal cortex.

Expression of activin A and its receptors in human pheochromocytomas

Activin A (a homodimer of two activin betaA subunits) has been shown to induce the neuronal differentiation of rat pheochromocytoma PC12 cells. We studied activin A and its receptor gene expression in human pheochromocytomas in vivo and in vitro to clarify the potential involvement of activin A in the pathophysiology of these tumors. We first screened 20 pheochromocytomas and nine normal adrenal tissues for activin betaA mRNA expression. Northern blots hybridized with specific oligonucleotide probes detected weak signals for activin betaA transcripts in pheochromocytomas. Both type I and type II activin receptor (ActR-I, ActR-IB and ActR-II) mRNA expression was also detectable in the pheochromocytoma tissues. In primary cultures of pheochromocytoma cells, expression of activin betaA mRNA was readily detectable by Northern blotting, and secretion of activin A into the conditioned medium was confirmed by an enzyme-linked immunosorbent assay. The expression of activin betaA mRNA and secretion of activin A were induced by (Bu)(2)cAMP after 1 and 3 days of treatment (all P<0.05). A protein kinase inhibitor, staurosporine, inhibited the basal and (Bu)(2)cAMP-induced accumulation of activin betaA mRNA (P<0.05). In addition, induction of chromaffin phenotype by dexamethasone also inhibited the basal and (Bu)(2)cAMP-induced expression of activin A at both mRNA and protein levels (all P<0.05). In contrast, the expression of ActR-I and ActR-IB mRNAs was not affected by these agents in cultured pheochromocytoma cells. In summary, activin betaA subunit and activin receptors are expressed in human pheochromocytomas. Production of activin A in cultured pheochromocytoma cells is induced through the protein kinase A pathway, but reduced during chromaffin differentiation. Therefore, activin A may function as a local neurotrophic factor via an auto/paracrine manner in human pheochromocytomas.

Long-term outcome of classical 21-hydroxylase deficiency: diagnosis, complications and quality of life

A nationwide search of patients with classical 21-hydroxylase deficiency (21-OHD) was performed in Finland to determine the long-term outcome of the disease. In total, 108 patients were found. Fifty-four patients (50%, 31F, 23M) had deficiency of a salt-wasting form and another 54 (50%, 29F, 25M) had a simple virilizing form of 21-OHD. A significant number of severe complications suggestive of glucocorticoid deficiency was found. There were five deaths (4.6% of all) possibly connected with cortisol deficiency. Ten additional patients (9.3% of all) had been acutely admitted 14 times in all due to symptoms of glucocorticoid deficiency. These symptoms included sudden loss of consciousness, convulsions and severe fatigue. Afterwards, permanent neurological defects were detected in two of these patients. Finally, a cross-sectional study was carried out to establish an estimate of the long-term outcome of the disease. Thirty-two (55%) of the 58 patients aged 16 y or more participated in this study. The patient group did not differ from the general Finnish population in terms of education. Three of the patients (5%) had retired prematurely. Surprisingly, the patients felt that their health-related quality of life, as reported in the RAND-36 questionnaire, was better than that of the general Finnish population (p = 0.023). However, as a significant number of all patients did not participate in this study, the quality of life evaluation results must be interpreted with caution. In conclusion, a significant number of complications was found among patients treated for classical 21-OHD. Nevertheless, the disease has a favourable outcome in terms of quality of life.

Adrenal suppression, evaluated by a low dose adrenocorticotropin test, and growth in asthmatic children treated with inhaled steroids

The aim of the present study was to evaluate the prevalence of adrenal suppression and growth retardation in children using moderate doses of budesonide or fluticasone propionate. Seventy-five asthmatic children were randomly divided into three treatment groups: 30 to the fluticasone propionate (FP), 30 to the budesonide (BUD), and 15 to the cromone (CROM) group. FP doses were 500 microg/day during the first 2 months and 200 microg/day thereafter. The respective BUD doses were 800 and 400 microg/day. A low dose ACTH (0.5 microg/1.73 m2) test was performed before treatment and 2, 4, and 6 months later. The test was considered abnormal if the stimulated serum cortisol concentration was more than 2 SD lower than the pretreatment mean (<330 nmol/L). The low dose ACTH test was abnormal after both the high and low steroid doses in 23% of the children. At the 4 month measurement there were more abnormal tests in the BUD (n = 9) than in the FP (n = 5) group (P < 0.05). At that time also the stimulated concentration of serum cortisol was lower in the BUD than in the CROM group (P < 0.01), whereas the difference between the FP and CROM groups was not significant. During the study year the mean decrease in height SD score was 0.23 in the children treated with BUD, 0.03 in the children treated with FP, and 0.09 in the children treated with CROM; the difference between the BUD and FP groups was significant (P < 0.05). In conclusion, the low dose ACTH test revealed mild adrenal suppression in a quarter of the children using moderate doses of inhaled steroids. A FP dose of 200 microg/day caused less adrenal and growth suppression than did a BUD dose of 400 microg/day.

Risk of enzyme allergy in the detergent industry

OBJECTIVES

To assess the prevalence of enzyme sensitisation in the detergent industry.

METHODS

A cross sectional study was conducted in a detergent factory. Sensitisation to enzymes was examined by skin prick and radioallergosorbent (RAST) tests. 76 Workers were tested; 40 in manufacturing, packing, and maintenance, and 36 non-exposed people in management and sales departments. The workers were interviewed for work related respiratory and skin symptoms. Total dust concentrations were measured by a gravimetric method, and the concentration of protease in air by a catalytic method.

RESULTS

Nine workers (22%) were sensitised to enzymes in the exposed group of 40, whereas none were sensitised in the non-exposed group. All the sensitised people had symptoms at work; all had rhinitis and one had asthma. Protease concentrations were generally < 20 ng/m3, but occasional peak values up to 80 ng/m3 were detected in the packing and maintenance tasks, and high values of > 1 microgram/m3 in the mixing area.

CONCLUSION

Despite the use of encapsulated enzyme preparations, high enzyme concentrations in workplace air are possible, resulting in a higher risk of sensitisation than expected.

Pituitary gonadal axis and child rate in males with classical 21-hydroxylase deficiency

Though appropriate glucocorticoid substitution therapy should abolish both cortisol deficiency and adrenal androgen excess in patients with 21-hydroxylase deficiency (21-OHD), the long-term outcome is not always satisfactory. There are several reports on low adult height in both male and female patients, and impaired fertility has been reported in females with 21-OHD. There are only few reports on gonadal function of adult male patients with 21 -OHD. In this study, we calculated the child rate of all the 29 diagnosed adult Finnish males with classical 21-OHD and compared it with the mean child rate of the whole Finnish male population with equal age distribution. Sixteen males with 21-OHD and their age-matched healthy controls were further examined in a cross-sectional study. Auxology and pituitary gonadal axis were examined in both patients and controls. Testicular ultrasonography of the patients was also performed. The mean child rate of the 29 males with 21-OHD was 0.07 which was significantly lower (p<0.001) than that in the Finnish male population of the same age (0.34). In the cross-sectional study, males with 21-OHD had serum testosterone, inhibin B, LH and FSH concentrations comparable to those of healthy controls and reference values. Serum DHEA-S concentrations were remarkably low, even in the undersubstituted males with 21-OHD (p<0.001, compared with the healthy controls). In the patient group, serum inhibin B concentration did not correlate with serum FSH concentration. Adrenal rest tumors of the testicles were found in two undersubstituted males with 21-OHD. In conclusion, our study suggests normal pituitary and gonadal function but reduced child rate in adult males with 21-OHD. This might be explained by suboptimal psychosocial adaptation to the chronic disease. However, the patients in this study were young and the final child rate may become essentially higher.

Impaired development of bone mineral density during chemotherapy: a prospective analysis of 46 children newly diagnosed with cancer

Osteopenia and osteoporosis are becoming increasingly recognized in children with cancer, though reasons for these changes are poorly understood. The purpose of the present study was to evaluate longitudinal changes in bone mineral density (BMD) and bone turnover in newly diagnosed children with a malignancy. Lumbar spine (L2-L4) and femoral neck bone mineral density (BMDareal, g/cm2) was measured by dual-energy X-ray absorptiometry in 46 children (age 2.9-16.0, median 8.0 years; 15 leukemias, 12 lymphomas, 19 solid tumors) at diagnosis, and after 6 months from the baseline. The apparent volumetric bone mineral density (BMDvol) was calculated to minimize the effect of bone size on BMD. Serum levels of osteocalcin (OC), type I collagen carboxy-terminal propeptide (PICP), and type I collagen carboxy-terminal telopeptide (ICTP) were analyzed at diagnosis, and during a 6-month follow-up. A significant decrease in lumbar BMDvol (-2.1%, p < 0.05), and in femoral BMDareal (-9.9%, p = 0.0001) and BMDvol (-8.5%, p = 0.0001) was observed after 6 months when compared with baseline measurements. The markers of bone formation (PICP, OC) were significantly decreased, and the marker of bone resorption (ICTP) was significantly increased at diagnosis as compared with normal values. By the end the follow-up, the levels of PICP and OC were normalized, whereas the level of ICTP continued to increase indicating that there was a negative balance in bone turnover. A deficient accumulation of bone mass might predispose children with a malignancy to impaired development of peak bone mass. A controlled study determining the benefits of an early intervention on bone turnover should be considered in these patients.

Disturbance in bone turnover in children with a malignancy at completion of chemotherapy

BACKGROUND

Osteoporosis and pathological fractures have been observed in children with a malignancy. The mechanisms of osteopenia in childhood malignancies have not been well established. The purpose of the present study was to evaluate changes in bone turnover and in bone hormonal metabolism in children with a malignancy at completion of their chemotherapy.

PROCEDURE

Serum levels of human intact osteocalcin, type I collagen carboxyterminal propeptide (PICP), type I collagen carboxyterminal telopeptide (ICTP), 25-hydroxyvitamin D [25-(OH)-D], 1,25-dihydroxyvitamin D [1, 25-(OH)(2)-D], intact parathyroid hormone, insulin-like growth factor I (IGF-I), IGF binding protein 3 (IGFBP-3), alkaline phosphatase, calcium, and phosphate were analyzed in 22 children with acute lymphoblastic leukemia and in 26 children with other malignancies. Results were expressed as Z-scores [mean (95% confidence intervals)] relative to healthy Caucasian-children.

RESULTS

The marker of collagen degradation (ICTP) was significantly increased [1.43 (1.10-1.76), P < 0.0001] compared to reference values, whereas the markers of bone formation (PICP, osteocalcin) were not changed [0.07 (-0.55 to 0.49), 0.35 (-0.05 to 0.74), respectively, NS]. Serum 25-(OH)-D, 1,25-(OH)(2)-D, and calcium were significantly reduced [-0.65 (-0.87 to -0.42), -0.68 (-0.92 to -0. 42), -1.42 (-1.80 to -1.04), P < 0.0001, respectively].

CONCLUSIONS

Disturbance in bone turnover with low serum 25-(OH)-D, 1, 25-(OH)(2)-D, and calcium was observed in children with a malignancy at completion of their chemotherapy. A controlled study determining the possible benefits of vitamin D and calcium supplementation on bone turnover could be considered in these patients.

Regulation of neuropeptide Y mRNA expression in cultured human pheochromocytoma cells

The expression of the neuropeptide Y (NPY) gene varies considerably in human pheochromocytomas, but the mechanisms for this variation have not been clarified. To investigate the regulation pattern of the NPY gene in human pheochromocytomas, we screened 16 pheochromocytomas and 9 normal adrenal tissues with Northern blots. The expression level of NPY mRNA in normal adrenal medulla was low and relatively constant, while the pheochromocytomas showed a very wide variation in NPY mRNA levels in both malignant and benign tumors. This indicates that NPY gene expression is not correlated with malignancy in pheochromocytomas. In primary cultures of human pheochromocytoma cells, nerve growth factor treatment (causing neuronal differentiation) increased NPY mRNA accumulation 2- to 5-fold (P < 0.05). NPY mRNA levels were also induced by protein kinase modulators (Bu)(2)cAMP and staurosporine in the cultures (P < 0.05). In contrast, treatment with dexamethasone and IGF-II (causing or linked with chromaffin differentiation) reduced NPY mRNA accumulation (P < 0.05). These data show that the regulation pattern of NPY mRNA expression in cultured human pheochromocytoma cells is different from that previously described in rat pheochromocytoma PC12 cells. Regulation of NPY mRNA expression in primary cultures by these differentiating factors suggests that the expression of NPY mRNA in pheochromocytoma tissues may be associated with the neuronal differentiation of the tumor cells affected by multiple factors.

Alterations in bone turnover and impaired development of bone mineral density in newly diagnosed children with cancer: a 1-year prospective study

In the present study, longitudinal changes in bone mineral density, bone turnover, and bone hormonal metabolism were evaluated in newly diagnosed children with cancer. Lumbar spine (L2-L4) and femoral neck bone mineral densities (grams per cm2) were measured by dual energy x-ray absorptiometry in 28 children (age, 2.9-16.0 yr; median, 8.0 yr; 10 acute lymphoblastic leukemias, 18 solid tumors) at diagnosis and after a 1-yr follow-up. Apparent volumetric density (grams per cm3) was calculated to minimize the effect of bone size on BMD. Serum levels of osteocalcin (OC), type I collagen carboxyl-terminal propeptide (PICP), and type I collagen carboxyl-terminal telopeptide were measured serially during the study. Serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, insulin-like growth factor I (IGF-I), and IGF-binding protein-3 were analyzed at diagnosis and at 1-yr follow-up. A significant decrease in femoral bone mineral density and apparent volumetric density was observed during the year after diagnosis [(mean (SD), -10.1% (8.8%) and -11.3% (8.1%) respectively; P < 0.01], whereas age- and sex-matched controls showed annual increments of +5.4% (7.7%; P < 0.01) and +0.7% (5.7%; P = NS) respectively. The markers of bone formation (PICP and OC) were significantly decreased at diagnosis. By the end of the follow-up, PICP and OC were normalized, whereas the marker of bone resorption (type I collagen carboxyl-terminal telopeptide) was significantly increased. Reduced levels of 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and IGF-binding protein-3 were observed during the study. To conclude, increased bone resorption and impaired development of femoral bone density were observed in children with cancer during chemotherapy. Deficient accumulation of bone mass may lead to impaired development of peak bone mass and predispose children with cancer to increased risk of osteoporosis and diminished skeletal resistance to fractures later in life.

pG2 gene expression and its regulation in human adrenocortical and medullary tumors

The cDNA clone pG2 was originally isolated from a human pheochromocytoma. The respective gene was found to be strongly expressed in normal adrenal zona glomerulosa and medulla, as well as in Conn's adenomas and pheochromocytomas. To shed more light on the expression and regulation of the pG2 gene, we investigated its expression in a wide variety of different adrenal neoplasms and cultured adrenal cells. Northern blot analysis was used to determine the steady state level of pG2 mRNA. Besides normal adrenals, Conn's adenomas and pheochromocytomas, we found abundant expression of pG2 mRNA in Cushing's, virilizing and nonfunctional adrenocortical adenomas and carcinomas, as well as in hyperplastic adrenals. The relative levels of pG2 mRNA in various adrenocortical tumors were not significantly different from those in normal adrenals and pheochromocytomas. In primary cultures of normal adrenal cells, treatment with adrenocorticotropin induced a 3- to 15-fold increase in the expression of pG2 mRNA (P<0.01), and this effect was reproduced by incubation with (Bu)2cAMP. In cultured pheochromocytoma cells, treatment with (Bu)2cAMP and a protein kinase inhibitor, staurosporine, increased pG2 mRNA accumulation (2- to 4-fold over the control level, P<0.01, and 3- to 8-fold, P<0.01, respectively). These results indicate that pG2 is widely expressed in normal and pathological adrenal tissues from both cortical and medullary origin, which eliminates its usefulness as a specific marker for zona glomerulosa or medullary adrenal tumors. Accumulation of pG2 mRNA is regulated by multiple differentiating factors through different pathways in primary cultures of normal adrenal and pheochromocytoma cells.

Reduced bone density at completion of chemotherapy for a malignancy

OBJECTIVES

Osteoporosis and pathological fractures occur occasionally in children with malignancies. This study was performed to determine the degree of osteopenia in children with a malignancy at completion of chemotherapy.

METHODS

Lumbar spine (L2-L4) bone mineral density (BMD; g/cm2) and femoral neck BMD were measured by dual energy x ray absorptiometry in 22 children with acute lymphoblastic leukaemia (ALL), and in 26 children with other malignancies. Apparent volumetric density was calculated to minimise the effect of bone size on BMD. Results were compared with those of 113 healthy controls and expressed as age and sex standardised mean Z scores.

RESULTS

Patients with ALL had significantly reduced lumbar volumetric (-0.77) and femoral areal and volumetric BMDs (-1.02 and -0.98, respectively). In patients with other malignancies, femoral areal and apparent volumetric BMDs were significantly decreased (-0.70 and -0.78, respectively).

CONCLUSIONS

The results demonstrate that children with a malignancy are at risk of developing osteopenia. A follow up of BMD after the completion of chemotherapy should facilitate the identification of patients who might be left with impaired development of peak bone mass, and who require specific interventions to prevent any further decrease in their skeletal mass and to preserve their BMD.

Tracing past population migrations: genealogy of steroid 21-hydroxylase (CYP21) gene mutations in Finland

The genealogic origin of steroid 21-hydroxylase gene (CYP21) mutations and associated haplotypes was determined in 74 unrelated Finnish families with CYP21 deficiency (congenital adrenal hyperplasia, CAH). These families account for two thirds (85/119) of all diagnosed patients of Finnish descent found in this country. We recently demonstrated that multiple founder mutations each associated with a particular haplotype can be found in Finland. Interestingly, some of the haplotypes were identical to those observed in various European populations, whereas others have not been described elsewhere, indicating a local and perhaps a more recent origin. In the present report we show that each of the major founder haplotypes originates from a particular geographic region of Finland. Thus many local genetic isolates are to be expected in Finland. Our finding is in a clear contrast to the genetic diseases known as the 'Finnish disease heritage', in which only one mutation usually predominates. Some of the CYP21 haplotypes proved very informative for analysis of the history of the Finnish population. For example, the origin of one frequent haplotype was shown to cluster in a region assumed by archaeological data to be a major site of immigration by settlers of either Scandinavian or Baltic origin during the first centuries AD. As this haplotype is frequent in many European patient populations, we provide independent genetic evidence of this Iron Age immigration. On the other hand, another frequent haplotype found solely in Finland reflects a more recent (post 15th century) settlement expansion. Consequently, well characterised and sufficiently frequent autosomal gene markers can provide useful information on migrations both between and within populations.

Expression of insulin-like growth factor binding protein 1-6 genes in adrenocortical tumors and pheochromocytomas

The insulin-like growth factor (IGF) system appears to be important in the regulation of adrenal growth and hormone synthesis. As IGF-binding proteins (IGFBPs) modify IGF bioactivity, we investigated the expression of IGFBP 1-6 genes in different adrenal tumors and hyperplasias to further clarify the role of the IGF system in adrenal pathophysiology. IGFBP-1 mRNA levels were too low to be detected by Northern blot analysis, but could be found by RT-PCR in some tumors and hyperplastic adrenals. Other IGFBPs were detected by Northern blotting. IGFBP-3 mRNA levels were very low in normal adrenals. In adrenal tumors and hyperplastic adrenals, IGFBP-3 mRNA expression was usually higher than in normal adrenals. In hormonally active adrenocortical carcinomas, IGFBP-2, -4, -5 and -6 mRNA levels were lower than in nonfunctional carcinomas and normal adrenals. The low IGFBP mRNA expression in the hormone-producing carcinomas was associated with high IGF-II mRNA content. In adrenocortical adenomas from patients with Cushing's or Conn's syndrome, mean IGFBP mRNA levels were higher than in normal adrenals or in hormonally inactive adenomas. In nodular and bilateral hyperplasias, IGFBP-2, -3 and -4 mRNA expression was on average higher than in normal adrenals but varied substantially, as did IGFBP mRNA levels in pheochromocytomas. In comparison to normal adrenals, pheochromocytomas expressed on average higher levels of IGFBP-2 and -4 but less IGFBP-5 and -6 mRNAs. Our data show that the six IGFBPs 1-6 are expressed at variable level in adrenal tumors and hyperplasias. The low level of IGFBP mRNAs in hormonally active adrenocortical carcinomas was of particular interest.

Expression of inhibin alpha in the human adrenal gland and adrenocortical tumors

We studied the expression of inhibin alpha-subunit in normal and hyperplastic adrenal glands, as well as in various adrenocortical tumors. The protein expression of inhibin alpha was performed by immunohistochemistry. Virilizing adenomas showed strong immunoreactivity against monoclonal inhibin alpha-subunit antibody, whereas other adenomas were only weakly positive or completely negative. In the adrenal cortex no inhibin alpha immunoreactivity was detected in the zona glomerulosa. Zona fasciculata showed weak staining for inhibin alpha, however, strong immunostaining was detected in zona reticularis both in normal and hyperplastic adrenal glands. Adrenal medulla was negative for inhibin alpha. In conclusion, we show high expression of inhibin alpha subunit in zona reticularis of normal and hyperplastic adrenal glands as well as strong expression in virilizing adenomas.

Adrenocortical cells are the site of secretion and action of insulin-like growth factors and TNF-alpha

Insulin-like growth factors I and/or II are expressed in adrenal cells, and modulate their proliferation and steroid hormone synthesis suggesting that they may function as paracrine/autocrine factors. In some species, at least ACTH induces insulin-like growth factor synthesis. Thus, these peptide growth factors mediate at least some of the effects of ACTH on adrenocortical cell proliferation and differentiation. Human fetal adrenals express insulin-like growth factor II gene abundantly and ACTH-dependently, while in adult adrenals, the expression is low and no ACTH dependent regulation has been demonstrated. Hormonally active adrenocortical carcinomas and virilizing adenomas express insulin-like growth factor II gene abundantly. This phenomenon is associated with reduced expression of two putative tumor suppressor genes (H19 and p57KIP2) locating on the same genomically imprinted locus on human chromosome 11p15.5. Tumor necrosis factor-alpha belongs to the cytokines which modulate hypothalamic-pituitary-adrenal axis. It is a potent inducer of ACTH secretion but, at the adrenal level, it seems to mainly inhibit ACTH-induced steroidogenesis and also insulin-like growth factor II expression. It is produced in adrenocortical steroidogenic cells in addition to macrophages, which suggests that tumor necrosis factor-alpha may have some autocrine/paracrine functions in the adrenal cortex.

Reduced bone mineral density in long-term survivors of childhood acute lymphoblastic leukemia

PURPOSE

Osteoporosis and pathologic fractures are occasionally found in patients with childhood acute lymphoblastic leukemia (ALL). This study was performed to determine the degree of possible osteopenia in long-term survivors of childhood ALL.

PATIENTS AND METHODS

Lumbar spine (L2-L4) and femoral neck bone mineral densities (BMDs) (g/cm2) were measured in 29 survivors (aged 12 to 30 years, median 17) of childhood ALL 2 to 20 (median 8) years after discontinuation of chemotherapy. These results were compared with those from 273 healthy controls and expressed as a percentage of the age- and sex-matched control values (mean +/- standard deviation).

RESULTS

Lumbar and femoral BMDs were significantly reduced in survivors of childhood ALL. Particularly, male gender (lumbar: 91.7 +/- 10.4%, p = 0.008; femoral: 91.9 +/- 11.3%, p = 0.005) and a history of cranial irradiation (lumbar: 93.0 +/- 8.9%, p = 0.005; femoral: 94.4 +/- 13.3%, p = 0.03) were associated with low lumbar and femoral BMDs.

CONCLUSIONS

The detected deficit in bone density in survivors of childhood ALL may predispose these patients to osteoporotic fractures later in adulthood. A follow-up of BMD in survivors of childhood ALL should facilitate the identification of patients who would require specific therapeutic interventions to prevent further decrease of their skeletal mass and preserve their BMD.

Adrenomedullin gene expression and its different regulation in human adrenocortical and medullary tumors

Adrenomedullin (ADM) is a polypeptide originally discovered in a human pheochromocytoma and is also present in normal adrenal medulla. It has been proposed that ADM could be involved in the regulation of adrenal steroidogenesis via paracrine mechanisms. Our aim was to find out if ADM gene is expressed in adrenocortical tumors and how ADM gene expression is regulated in adrenal cells. ADM mRNA was detectable by Northern blotting in most normal and hyperplastic adrenals, adenomas and carcinomas. The average concentration of ADM mRNA in the hormonally active adrenocortical adenomas was about 80% and 7% of that in normal adrenal glands and separated adrenal medulla respectively. In adrenocortical carcinomas, the ADM mRNA concentration was very variable, but on average it was about six times greater than that in normal adrenal glands. In pheochromocytomas, ADM mRNA expression was about ten times greater than that in normal adrenals and three times greater than in separated adrenal medulla. In primary cultures of normal adrenal cells, a protein kinase C inhibitor, staurosporine, reduced ADM mRNA accumulation in a dose- and time-dependent fashion (P < 0.01), whereas it simultaneously increased the expression of human cholesterol side-chain cleavage enzyme (P450 scc) gene (a key gene in steroidogenesis). In cultured Cushing's adenoma cells, adrenocorticotropin, dibutyryl cAMP ((Bu)2cAMP) and staurosporine inhibited the accumulation of ADM mRNA by 40, 50 and 70% respectively (P < 0.05), whereas the protein kinase C activator, 12-O-tetradecanoyl phorbol 13-acetate (TPA), increased it by 50% (P < 0.05). In primary cultures of pheochromocytoma cells, treatment with (Bu)2cAMP for 1 and 3 days increased ADM mRNA accumulation two- to threefold (P < 0.05). Our results show that ADM mRNA is present not only in adrenal medulla and pheochromocytomas, but also in adrenocortical neoplasms. Both protein kinase A- and C-dependent mechanisms regulate ADM mRNA expression in adrenocortical and pheochromocytoma cells supporting the suggested role for ADM as an autocrine or paracrine (or both) regulator of adrenal function.

Population-wide evaluation of disease manifestation in relation to molecular genotype in steroid 21-hydroxylase (CYP21) deficiency: good correlation in a well defined population

We report a population-wide analysis of all patients with 21-hydroxylase deficiency (21-OHD) found in Finland, a country with a genetically well defined population, in which the effects of other genetic and environmental factors on the phenotype can be expected to be low. In total, 120 patients were identified, and their clinical status was evaluated. Blood samples for CYP21 genotype determination could be obtained from 78 (65%) patients, and their phenotypes were compared with their genotypes. In general, the severity of gene defects correlated well with clinical expression. All patients carrying mutations with the most drastic effects on enzymatic activity had the salt-wasting form of 21-OHD. The I2 splice mutation, which in some reports has been connected with clinical variation, was constantly associated with severe mineralocorticoid deficiency. However, patients with I172N as the determining mutation expressed a wide spectrum of phenotypes; the variation could not be attributed to additional mutations. Although genetically affected males with the nonclassical form had not been clinically diagnosed, our study suggests that nonclassical 21-OHD is substantially more rare in Finland than elsewhere, as indicated by both clinical evaluation and mutational screening.

Divergent association of apolipoprotein E polymorphism with vascular disease in patients with NIDDM and control subjects

We analysed a well-characterized group of 83 patients (43 men, 40 women; mean age +/- SEM: 65.5 +/- 0.6 years at the 10-year examination) with non-insulin-dependent (Type 2) diabetes mellitus (NIDDM) and in 123 control subjects (56 men, 67 women; mean age +/- 0.9 years) retrospectively for the relationship of apolipoprotein E (apo E) genotypes (E2/3, E3/3 vs E3/4, E4/4) to the incidence of clinical macrovascular disease and its risk factors and the incidence of microvascular complications of diabetes during the first 10 years of NIDDM, as well as carotid intima-media thickness measured by B-mode ultrasound at the 10-year examination. In patients with NIDDM, apo E4 genotype showed no relationship to clinical events or carotid intima-media thickness. However, in the control subjects with apo E4, the incidence of non-fatal myocardial infarction during the follow-up was increased (apo E4 positivity: 17.1%; apo E4 negativity 5.1%; p = 0.035) and they had higher common carotid intima-media thickness than those with apo E2/3 or apo E3/3 (1.15 +/- 0.05 mm vs 1.01 +/- 0.03 mm, p = 0.008). Apo E genotype groups showed no relationship to microvascular complications of diabetes, although control subjects with apo E4 positivity showed a higher frequency of microalbuminuria than those lacking apo E4. We conclude that apo E4 was a marker of vascular disease and increased atherosclerosis in non-diabetic subjects, whereas in the diabetic patients these relationships were absent. It is likely that NIDDM per se influences the vascular risk so overwhelmingly that the effects of other risk factors are obscured.

Ribonucleic acid expression of the CLA-1 gene, a human homolog to mouse high density lipoprotein receptor SR-BI, in human adrenal tumors and cultured adrenal cells

Human CLA-1 is homologous to the mouse SR-BI gene, which was recently identified as a high density lipoprotein receptor involved in selective cholesterol uptake in rodent adrenal cells. We screened 42 normal and pathological adrenal samples by Northern blotting and found abundant expression of CLA-1 messenger ribonucleic acid (mRNA) in normal adult and fetal adrenals, adrenocortical adenomas, and hyperplasias. Adrenocortical carcinomas and the adrenals adjacent to Cushing's adenomas contained less CLA-1 mRNA than normal adrenals. CLA-1 mRNA was also highly expressed in a Leydig cell tumor, but much less in liver, kidney, and pheochromocytomas. The accumulation of CLA-1 mRNA in primary cultures of normal adrenocortical cells was up-regulated by ACTH in a dose- and time-dependent manner. Both dibutyryl cAMP and staurosporine increased the basal expression of CLA-1 mRNA. Although there was no additive effect of ACTH and dibutyryl cAMP, staurosporine slightly enhanced the stimulatory effect of ACTH on the expression of CLA-1 mRNA. The abundant expression of CLA-1 mRNA and its regulation by the physiological hormone ACTH in human adrenal cells suggest that CLA-1 has a role in adrenal steroidogenesis, probably as a lipoprotein receptor mediating the selective cholesterol uptake in these cells.

Genetic predisposition to phaeochromocytoma: analysis of candidate genes GDNF, RET and VHL

Inherited predisposition to phaeochromocytoma (MIM No 171300) occurs in multiple endocrine neoplasia type 2 (MEN 2) (MIM No 171400), von Hippel-Lindau (VHL) disease (MIM No 199300), and neurofibromatosis type 1 (NF1) (MIM No 162200). In addition, familial phaeochromocytoma alone has also been reported and we and others have identified germline VHL mutations in five of six kindreds analysed previously. Germline mutations in the RET proto-oncogene, which encodes a receptor tyrosine kinase, and in the VHL tumour suppressor gene cause MEN 2 and VHL disease, respectively. To further investigate the genetics of phaeochromocytoma predisposition, we analysed three groups of patients with no evidence of VHL disease, MEN 2 or NF1: Group A, eight kindreds with familial phaeochromocytoma; Group B, two patients with isolated bilateral phaeochromocytoma; and Group C, six cases of multiple extra-adrenal phaeochromocytoma or adrenal phaeochromocytoma with a family history of neuroectodermal tumours. Germline missense VHL mutations were identified in three of eight kindreds with familial phaeochromocytoma. A germline VHL mutation was also characterised in one of the two patients with bilateral phaeochromocytoma. No VHL or RET mutations were detected in the final group of patients with multiple extra-adrenal phaeochromocytoma or adrenal phaeochromocytoma with a family history of neuroectodermal tumours. The absence of germline VHL and RET gene mutations in many of these families suggested that other phaeochromoeytoma susceptibility loci may exist. Glial cell line-derived neurotrophic factor (GDNF) has been recently identified as a natural ligand for RET. Thus, it seems plausible that GDNF is a good candidate gene to play a role in phaeochromocytoma susceptibility. We searched for germline mutations in GDNF in 16 cases of familial phaeochromocytoma (groups A, B and C) and looked for evidence of somatic change in GDNF in 28 sporadic phaeochromocytomas, 12 MEN 2 phaeochromocytomas and five VHL phaeochromocytomas. No GDNF mutations were identified in patients with familial phaeochromocytoma disease, but a c277C-->T (R93W) sequence variant was identified in one of 28 sporadic tumours. This candidate mutation was identified in the germline and tumour tissue but was not present in 104 control GDNF alleles. GDNF sequence variants including R93W have been suggested previously to represent low penetrance susceptibility mutations for Hirschsprung disease and the R93W was not identified in 376 control alleles studied by others. These findings suggest that although GDNF mutations do not appear to have a major role in the pathogenesis of familial or sporadic phaeochromocytomas, allelic variation at the GDNF locus may modify phaeochromocytoma susceptibility.